Forced-draft air supply and control means for furnaces



Sept. 7, 194-8. K Z 2,448,891

7 FORCED DRAFT AIR SUPPLY AND CONTROL MEANS FOR FURNACES Filed NOV; 20. 1943 2 Sheets-Sheet 1 v I HEKZZ mu .1 \N I I 6N x Q C 3 NR u I 9 IN fih wwmw N PR I I I l I l I I I I I Sept. 7, 1948. p KATZ 2,448,891

FORCED DRAFT AIR SUPPLY AND CONTROL MEANS FOR FURNACES 2 Sheets-Sheet 2 Filed NOV. 20, 1943 v EPA Z232" Patented Sept. 7, 1948 um'rao PATENT orri'ce FORCED-DRAFT AIR AND SONTBOL .MEANS. FOR FURNACES Harry P. .Katz, Cleveland, Ohio 7 Application November 20, 1943, Serial No. 511,126

, Claims. 1

This invention relates tondraft control designed for general use but primarily for coal or wood fired furnaces and boilers intended for domestic use.

It is particularly aimed to provide a force airdraft control capable of automatic operation'with a blower thereof bya thermostat, and which controlcan be permanently attached-in thedraft opening of .theash-pit door.

It is further. ai-m'edto provide av novel; force draft control. including a twin-blower associated with a novel housing with which both blowers communicate, and which housing is controlled by a noveLshutter adapted to open to air inducted by theiblower and close automatically when the blower is idle.

It is also aimed to provide a novel housing and meansto mount the same, to protect the twin blower and motor against fine coal, dirt and the like. s

In addition, I to provide a means to enable the firebed to be maintained-longer, so as to require minimum use of the automatic blower, such means being in the nature of a check damper adjustably controlled as to position and adapted to. automatically close as the furnace door through which fuel is supplied, is open. Theadjustment of such damper will prevent the furnace from becoming overheated.

variousfadditional objects and advantages will become apparent and in part bepointed ont in the'description following taken in connection with accompanying drawings illustrating an onerative'embodiment.

' In said drawings;

Figure l is a view of the furnace embodying my improvement Figure 2 is an enlarged view, taken horizontally through the furnace door and showing the mounting of my improvements;

Figure 3 is a vertical sectional view taken on the line 3-3 of Figure 1; and

Figure 4 is a vertical sectional view taken on the line 4-4 of Figure 2.

Referring specifically to the drawings wherein like reference characters designate like or similar parts, It) represents a conventional coal or wood furnace which is adapted to be fired through an opening normally closed by a usual door at H, hinged in place as at l2. Such furnace has an ash-pit door at l3 also hinged in place as at H, and further has a discharge flue l5 and an airinlet duct at Hi. This duct I 6 has pivoted over its open outer end at H, a check damper l8. Lug

I9 is provided on this damper and a screw 2|! passes, rloosely through a .hole therein. and which screw is adjustable as to position through the manipulation of, a nut 21 thereon. Attached to the bolt 20- is a chain or other flexible element 2|, which is trained over pulleys 22 and 23, suspended from a ceiling 24 above the furnace and leadingwand being connected to a part of the door H suchasthe operating or latch handle 26 As a result, when the door H is opened, the. chain 2| will be sufllciently slack to enable the damper I8 to automatically close, while when the door is closed, the ch'ainwill be taut and thus the check damper will be automaticallyopened. Through the, adjustment ofythe bolt 21!; by,v reason of-the nut Hthreadedthereon, the check damper is adjustable tothe exact extent of opening that is desired at the. duct l6 ;in o r der,-to prevent the furnace from overheating. and at the same time aids. thefirebed i i-being maintained for the maximum period of time,1 without any other. controls such as-t-he automatic draft :blower controls as will now he described.

Reverting to the ash-pit door I3 it has the usuai draftopeningzl therethrough in which a draft duct 28, in. accordance with my invention, is disposedandiastenedin any suitable manner. It will be noted that a shutter or damper 31 is pivoted in the duct on a horizontal axis 32, the shutter being of a length to prevent movement pastthe vertical and also having a weight at 33, whereby the shutter will automatically close in the absence of a draft therethrough.

In connection with the invention, I use a twin blower structure generally designated A. This structure is a unit having an electric motor 33 on whose main shaft 34 are keyed suitable impellers or fans 35, each operating within a casing 36, having a discharge end or pipe 31 tightly but removably bolted to the duct 28 through part 38.

It will be noted that the casings 36 have their intake openings at their outer sides as at 39.

In order to prevent fine coal, dirt, or other foreign matter from affecting the motor 33 and the blowers, and preventing the transmission of undue heat thereto, as well as functioning in supporting the blower structure, I dispose over the same an apron or shield at 40, the same being detachably bolted as at 4| to the casing or frame of door 13. Also, in order to render the mounting of the shield 40 more stable, I provide outwardly extending ears 42 on inward extensions 43 of the shield 40. The ears 42 have openings 44 therethrough which are engaged each by a hook 45,

loosely pivoted as at 46 at opposite sides of the duct 28.

In order to open and close the intake openings 39 of the blowers, to any extent desired, closures 46 are adjustable thereover, being pivotally mounted on the bolts 41 passing therethrough and through the extensions 43 and which have wing-nuts 48thereon to facilitate manual manipulation. a I

The motor 33 is preferably under-automatic control, that is, control of a thermostat. When the motor operates, it forces a draft by inducin air through the openings 39 into the blowers and discharging it through the outlets 31 into the duct 28 and then into the ash-pit beneath the firebed. It will be realized that the action of the air or draft automatically opens the shutter 3| and that in the absence of such draft, the shutter automatically closes under the action of the weight 33. I

It will be realized that the check damper I8 will be automatically closed when the door is opened to'refuel the furnace, and that the closing thereof serves to give the natural draft to the furnace and aids in carrying'offsmoke While refueling. Z

Various changes may be resorted to provided they fall within thespirit and scope of the invention. F

I claim as my invention:

1. In combination with the ash-pit door of'a furnace, a forced draft unitmounted thereon in communication with the atmosphere and the interior of the furnace, the unit comprising a duct having one end communicatin with the furnace, a blower means associated therewith having an intake communicating with the atmosphere, and shutter means for the duct, biased so as to automatically close in the absence of draft, said shutter means being displaceable toopen position in the presence of a draft from the blower means, the blower means having a discharge pipe leading to the duct, and a shield extending from the duct rearwardly and downwardly over the blower means, devices positioning said'shield attached adjacent the lower end thereof and to the duct, and a closure mounted on said shield for the intake and adjustable relatively thereto.

2. In combination with the ash-pit door of a furnace,- a forced draft unit mounted thereon in communication with the atmosphere and the interior of the furnace, the unit comprising a duct having one end communicatingw-ith the furnace, a blower means associated therewith having an intake communicating with theatmosphere, and shutter means for theduct, biased so as to automatically close in the absence of draft, said shutter means being displaceable to 4 open position in the presence of a draft from the blower means, the blower means comprising a motor and blower elements operated thereby on opposite sides thereof, having discharge pipes communicating with the duct, and a shield extending from the duct over the blowers and motor, said shield having ears, and hooks extending from the duct engaging said ears whereby the'shield is retained in position. a

- 3;" In combination with the ash-pit of a furnace, a forced draft unit mounted thereon in communication with the atmosphere and the interior of the furnace, the unit comprising a duct havin one end communicating with the furnace, a blower means associated therewith having an intake communicating with the atmosphere, shutter means for the duct biased so as to automatically close in the absence of draft, said shutter means being displaceable to op n position in the presence of a draft from the blower means, the blower means-comprising a motor and blower elements operated thereby on opposite sides thereof having discharge 'pipes communicating with the duct, and a shield extending from theduct over the blowers and motor, said shield having ears, elongated elements fastened at opposite ends to the earsand to-the duct to retaina lower portion of the shield in position, and closures for-the intakes of the blower elements pivoted to the said ears for adjustment to control the closing and extent of opening of the said intakes.

4. A combination according to claim2 wherein the intakes have closurespivotally mounted on said ears for adjustment to control the closing and extent of opening of said intakes; Y

HARRY P. KATZ, I

REFERENCES CITED The following references areof record in the file of this patent? I UNITED STATES PATENTS Number Name Date 1,375,482 Bartlett Apr.'19, 1921 1,587,341 McVay Junel, 1926 1,944,984 Klippel' Jan, 30, 1934 2,031,652 Hopping Feb. 25,1936 2,037,598 Scheifele- Apr. '14, 1936 2,135,252 Grover 'Nov. 1, 1938 2,194,691 Cornell Mal 26, 1940 2,227,286" 'T'app Dec. 31, 1940 2,301,060 Livar 'Nov. 3, 1942 FOREIGN PATENTS Number Country Date 428,632- Great Britain Dec. 19; 1933 

